The rumors about the immigration checkpoint began Thursday morning. By 2 p.m., the account @MrCheckpoint tweeted: “NOW #InlandEmpire Immigration Checkpoint #Ontario near Euclid Ave & 60 Freeway.” As of 4 p.m. it had been retweeted 137 times.

Acknowledging the confusion, Twitter user @MrCheckpoint later tweeted: “Trying to figure out this whole immigration checkpoint thing going on in Ontario right now. I’m hoping we don’t see more of these..” The user later said the tweets were going to be deleted.

Ontario police Sgt. Ron Endo said the department was not conducting a checkpoint.

Endo said this was the first he had heard about an immigration checkpoint.

“It takes one person saying they saw something and it runs amok,” he said, referring to the spread of social media rumors.

Chino police Lt. Rodney Lombard said the department didn’t have any checkpoints scheduled Thursday or even this weekend. Lombard said Chino wasn’t notified of any other checkpoints being conducted in surrounding cities.

“It probably was a frivolous tweet,” he said.

Editor’s note: This story has been updated to clarify when the first tweet was sent.